Heat exchanger network (HEN) and water network (WN) are basic constituents of an integrated process system. Heat and water integration reduces significantly investment and operation costs of a plant and, also, is the important mean to reach requirements of sustainable industrial activity (clean production). The aim of the paper is twofold. First, we show how similarities and differences of the two problems influence the way they can be solved. Then, we address an overview of selected solution approaches developed by the author in Hyprotech Ltd (Canada) and by the research team in the Department of Chemical and Process Engineering of Rzeszow University of Technology.